Well.. maybe.. do you want to keep the legs long, or are you willing to compromise a little? There are ways to fix.. try moving the model root node up until the feet are properly placed on the floor. When you do this - make sure the animation is reset to the beginning, and then you'll need to update the pose preset in timeline, or it'll just go back to the original position when you start the mocap over again. Another thing you can do is shrink the model - try scaling it down, or try adjusting the morphs so she's shorter. If none of that works contact me on discord and I can help you out.